1. Technical Field
The present invention relates to interdental brushes with a brush portion having wires and filaments arranged on the periphery of the wires by disposing the filaments between the wires and then twisting the wires, and particularly to an interdental brush with improved filament retention, in addition to superior cleaning effectivity and reachability to minute portions.
2. Background Art
Conventionally, various proposals have been made for this kind of interdental brushes. For example, Japanese Unexamined Patent Application No. 9-23928 proposes an interdental brush with a bristle arranged portion having two or more sections wherein adjacent sections arrange therein filaments of mutually different physical properties (material, hardness, thickness, color, and the like), thereby implementing a variety of required functions on a single interdental brush or implementing an interdental brush that provides for proposals for new applications with newly added functions. Japanese Registered Utility Model Publication No. 3139296 proposes an interdental brush wherein the filaments on the brush portion have formed thereon a plurality of depressions, thereby providing the interdental brush with improved interdental insertibility and cleanability, good comfortability, and superior durability. However, these conventional interdental brushes have been faced with some degree of limitation in improving the brush portion in respect of its cleaning effectivity and reachability to minute portions of teeth such as interdental corners.